Rotary underreamer



April i9, 1927., 1,625,208

M. C. HAZARD ROTARY UNDERREAMER Filed Oct. 13, 1923 INVENTOR. /fmm Mr/@ Patented pn lil,

UNl'lhll) FFEQE.,

'MERLXN G.l HAZARD, 0F HUNTXNGTON BEACH. CALIFORNIA, ASSIGNOR', BY DIRECT AND MESNE ASSIGNMENT' TO MARVEL OIL TOOL COMPANY, 0F HUNTINGTON BEACH, CALIFORNIA, .A CGRFRATION.

ROTARY UNDERREAMER.

Application filed October 13, 1923.

This invention relates to underrean'iers for use in enlarging' the'diameter ot a Well holea, and rotors particularly to an underreamer ilor use in tho rotary system ot drilling or consti-notiunY oil-Wells.

lleretotore. soule oit the rotary underroamers which have been employed tor enlaminelr a n'ell hole below a ivell casing); have had a decided tendency to look the cutters l employed in the underreamers in the reamina' or cuttingl position Where the underreamer cannot he Withdrawn through the woll casino'. ll'loreover, these prior underreaiuers have had a tendency to twist or F work b v hard strata or rock in the Well. hole with the result that a portion ot the Well hole is not properly reamed to the enlarged diameter and an abutment is lett inthe Well hole which will catch and obstruct the lowering' ot the Well casing. Furthermore, in the underreaminnl operation tbe heavy nrm-pulverized material scraped ott the sides ot the well hole tends to tall to the bottom ot the hole. Where it accumulates and is not ynfog'ierly removed by the iinshing `Huid sont down to the underreamer, With the result that this material aceunmlates in the bottom ot the Well hole and obstructs the lowering` of the underreamer, so that it is Anecessary to remove the underreamer and insert in place thereof a boringv tool to cut and mix up such. heavy material and remove the same from the Well. Furthermore, some oi the underreann-n's employed in the rotary system of drilling;` Wells have a decided tendency to produce a crooked hole.

(lne object ot this invention is to provide a `torni oit underreamer which may be em- `uloyed in the rotary system ot reaming or 40 enlarging' the bore of a Well hole below a ive-ll casing', which underreamer is so constructed that the cutters may be readily collapsed to the non-reamingr position at any time so that the underreamer may be With- (l drawn through the well casing'. I have found that by so constructing the underrean'ier, that in the cutting or roamingl position only the cutting,` blades oit the cutters extend beyond the body of the nnderreamer,

Serial No. 668,306.

the cutters may more readily be translated to the nonsrean'iingr position. This is due to the elimination ot zones between the cut ters `or cutters and body where the dbris or mud encountered, in the reaming operation may pack or clog` and tend to lock the cutters in the reaming` position. I have further found that by enclosing` the mechanism. which in the underreamer is employed for translating;` the cutters to or from the reaming position, in a chamber substantially sealed or closed. oill from communication either' With the flushinnl mud sent down to the reamer or With the mud and dbris in the well hole, the tendency ot suoli mecha nisiu to become locked in the 'teaming position during;` the operation oit the underreamer can be eliminated.

lefinother object of this invention is to pro` vide an under reamer which Will positively ream or enlarge all the bore of the Well hole Without forming' any shoulde or abutments in the Well hole which may later obstruct the lowering oit a Well casing. This is accomplished by so constructing the cutters that throughout the roaming operation an elongated vertical cutting edge is pre sented to the formation. which cutting` edge is ot such length that the nnderreamer eannot twist or Work by the hard strata encountered lin reaminp; the nell, but such hard strata will. be repeatedly acted upon by the cutters of the underreamer tlnoughout a relatively long` period. thus insuring that such hard strata will be completely out or sheared -from the Well hole.

Various other objects and advantages of this invention will be apparent from a description ot the preferred embodiment or method ot embodiment ot the invention, and will be presented througrh the practice and use ot the invention.

In the accompanyineY drawings l have illustrated one example of an underreamer embodyinnA the inventioi'i. in which:

Figure l is an elevation of an underreamer embodying the invention;

Figure 2 is an elevationat right angles to Fig. l;

Cai

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trai'usverseY section on: the

transverse section on the 3; and

ot the body extends afn'iixing andf centeringjirv blade 3 which preferably terminates in lishtail cuttinlfredgesl; The blade 3' andithe width oil. the cutting edges 4f is equal tothe diameter otthe' body 1 oi' the underreainer.

Onopposed sides ot the body 1 are torined Cutter-ways 6 which extend troni the lower endY of" the body upwardly in; al direction longitudinal'witlithe body to within a'shortdistance ofthe threaded stein Theways 6 are lirovidedwith cu ter blade openings 5 extending longitudinal. to the body, and said cutter blade' openings 5 are preferably arranged at right. angles to the cutting,l vedges yl of. the blade 3.. inwardly troni the openings or dove-tailed in cross-section and receive cutters 7` which are provided. with beveled shoulders 8 litting the dovetailed section oli the cutterways in one position.` rllhroughout substantially the entire length ot' the cut-ters a cutting. blade 9 extends which is shaped to pass through the openings ot the ways (i and" extend beyond the body 1 ot the reainer; The body of the cutters T is ot a le gth sub.- stantially equal. to the length ot"v the cutterv ways G ot the body 1 so that. in the reaining.

position said' ways siiibstantially enclose all parts ot the body excepting the blade 9 ot' the cutters, and thus inudi and debris cannot'. pack between the two cutters or in any zone etween the body 1 and cutters` 7. To nnpart the lateral inoveinent to the cutters TA which is essential to niove the cutters to or fi'oni the underreaniing position, rider surfaces 10 are torined on confronting surfaces ot' the body 1 and cutters T'. n this enibodinient ot' the invention one ot said ridder surfaces isfornied at the upper end' ot: each cutter-way G' and within the bottoni of the way G, said rider surface having' a verticali1 straightI section 11 joining a downwardly perspective.4 o'l one ot, theV The wavs 6 are enlare'ed'A when in the expanded position. A. second rider suriace 10 is 'l'ori'iied on the lowcr end of each cutter T, said rider 10 coinln'isine; a downwardly and inwardly beveled sui-tace 13 which joins a vertical surface ll, the vertical surdaco 1 -l extending; laterally inward 'treni the' cutter '7 a distance equal to the lateral distance between the surface 11 andthe bottonio't the w-ayvti. ln thisuianner, when the cutters 7 are translated-up and overtherider surfaces lO'the cutter blai'les t) are moved parallel to their vertical Cut'- ting edgeand the cuttingedge is thus posin tioued always substantially vertically in the uinlerreanier. lin the underreainer the length ot the cutter 7 niay be as great as found necessary t'or the reaniing operation, and this construction ot the cutters and body perinits ready changes in the length ottheeutt'er by siinply varying the length of the ways 6 and cutters T andwhere necessary the length ot' the body 1. io properly reanr the wcll'hole, the cutters 7 should be provided with a straight verticalv cutting edge oil a length greater than the di` ai'nete'rof' the body 1', and said straight edge lrsliould'terminate in an inwardly beveled or curving; edge 16 which curyes in a sulicientl distance so that when the cutters 7 are in the reainingi position the lower ends ot' hole torined by the l'ish-tail cutters and the long, straight or rerticaledge ol the cutters willrepeatedly contactr with the well hole, enlarging the saine and straightenine` the wellihole. Engaging the lower ends oi both cutters 7 is provided a head ll' whichV works ina slot 18 in the cutter blade 3.

Saidlhead 1T is lined to a rod 1U which eX*- tends axially upward through the body l ot the underreaniertitting relatiiely closely the lower end: ot' the body. ltlktending troni the upward endv olf the body is provided a springl enclosifnze'l cliainber 20 in which. is placed a coil-spring 21 enclosing the rod 19 and seated atv the bottoni ofthe springl enclosing chainber 2t) at one endl aud pressing' against a nut or head lixed to the' upper'end. ot. the rod 19. Said spring' is arranged so that there is normally apif 1 I piled a pressure on the rod 19 tendingl lo urge the rod` 19 vertically upward in the uinlerrt-mnier,` thus providing` iueans nor;

niallyurging the cutters to the reaining;

position. 23 indicates a closure screwed into the upper end ot the body which encloses the chai'nber 2() troni the flushing huid admitted: down the drill pipe.. Said chainloer 'is thus entirely enclosed t'roin contact either with the flushing fluid supplied to the underrealner or with dbris or niud found lun liu

lili) lit) in the well hole. Said chamber ZO may be and prete wably is packed with a lulnicant during the operation ot the iuiderreamer. 'lo prevent mud clogging .in the slot 18 in the blade 3, there is termed an edge 2t) at the lowerl end ol said lslot which will readily cut or divide mud tending to clog` or pack therein.

(,)n opposed sides olE the chamber 2o extend flushing ducts which join channels 25 extending longitudinally through the upper ridersl l() 'troni which the flushing `water is discharged .into the space between the cuts ters 7 and bottom ot the ways (5 when the said cutters are in the reaming` position to and through a channel 26 in the lower rider l() and discharged :t'rom the bottom end ot the cutters 7.

In operation.` the cutters T are pressed down against the head l? until the cutters 7 can assume the collapsed er non-roaming position when they are pressed in the body and can be tied by a cord or held by other suitable mea-us in the non-roaming position. The umlerreamer Vis then lowered into the well casing and as the reamer enters the well casing the cord is cut. lVhen the reamer is lowered below the well casing the cutters 7 will be released and will be forced upward by the tension in the spring 21 over the rider surface l0 into the reaming position where the cutter edges .l5 and 1G extend beyond the body ot the reamer and are in position to ream a hole ot sutlicient size to permit the well casing to be lowered. During` the reamingoperation the blade 3 and lislrtail cutter edge -l continually stir and cut up the heavy material dislodged trom the sides ot the well hole and dropped in front ol the underreamer so that flushing Huid sent through the ducts 2land discharged lroni below the cutters may carry this material back and out oit the well. The blade 3 also serves to guide the underreamer during the roaming operation and thus insures the drilling ot' a straight hole. To this end. the length ot the cutting edge .l5 aids, in that through repeated contact with each portion ot the lormation such cutting edge l5 tends to straight` en the well hole. lt will be observed that in the roaming position the entire part oit both the cutters 'T and the members employed to actuate the cutters are held enclosed by or flush against the body so that there is no space :tor the accumulation oit mud which will prevent the collapse of the cutters. l\loreover, the spring 2l .is entirely closed ol'l' :trom either the mud or debris encountered in the drilling operation or trom the lushing `[luid sent down to the umlerreanier, and thus mud or debris cannot clog in between the parts ot the mechanism employed lor actuating the cutters. Thus it is found that the underreamer constructed according to this .invention can at all times readily be collapsed to the non-reaming position and with dra wu through the well casing.

Another advantage oit the imderreamer herein descrilie-:l that when sott lornjuitions which tend to cave in are encountered, this urulerreamcr may be employed both lor tno original drilling o' the hole. and` the reaming' operation.y and in this way the hole drilled and reamed without danger ot a cavein occurriug` Another advantage of this invention is that the cutters may be made as long as desired and this is acconu'ilishcd simply by varying the length ot the body and cutters. Thus an underreamer is provided which will present a cutting edge to the Vformation which cutting may be several times greater in length than the diameter ol the body.

While the underreamer herein discribed is well suited tor the purpose ot this invention, it not intended to limit the invention to the specific construction or details thereof it'orming a part ot the preferred embodiment ot the invention, but various changes in the details ot construction and arrange nient ot parts may be made without departing from the spirit ot the invention. This invention is ot the scope set toi-th in the accompanying claims.

l claim:

l. A rot-ary well underreamer connnfising a body having undercut cutter ways extend ing longitudinally along and parallel with the axis of the body, spaced rider surfaces parallel with the cutter ways, cutters slidable in said ways and arranged so that in the roaming position the cutters bear on said rider surfaces back oi" the cutting edges ot said cutters with the cutting edges only extending from the ways, and spring means normally urging the cutters to the roaming position.

2. A rotary underreamer comprising a body having undercut cutter ways extending longitudinally along and parallel with the axis ot the body, rider surfaces parallel with the cutter ways, elongated cutters slid-able in the ways and arranged so that in the roaming position the cutters bear on said rider surfaces back of the cutter surfaces of the cutters with the cutting edges extending trom the ways, and spring` means normally urging the cutters to the roaming position, and flushing` ducts extending through the body.

3. A rotary underreanier comprising a body having undercut cutter ways extending longitudinally along and parallel with the axis of the body, spaced rider surfaces eX- tending parallel with said ways, elongated cutters slidable in the ways and arranged so that in the roaming position the cutters bear on said rider surfaces back of the cutter surfaces ot the cutters with the cutting edges extending from the ways, spring means norlill) llt) nially urging the onttereV to the' reirining p0*- eition, flushing duets` extending through the body` u serineV eni'losinff ehun'iber in Suid l an i m body, and a closure lor the eliznnber eneloeinn' the elnunber frein communication with said flushing duels.

l.. A rotary underreainer comprising,` :i body having* longituilinul undercut eulter ways extendingl purullel with tle axis oi said body, eutters elidul'ile in :luid Wnye and having substziutiully vertical eulzliing' edgee of relatively grenier length llnin the reunri diameter olf the underrezrn'ier, epeeed ri. Surfaces pe nllel with seid ways, the euttereK being' arranged so that in roaming the eutlzers beur on Suid rider surfaces beek of the euttine` edges with tbe cutting; edges only extendingtroni the we Ls, and ineens yieldingly rnfiintuinire;` the cul-eers in z reuniing position.

A rotary Well umlerreanier comprising,Y n. body haring longitudinal undercut cutter ways (intending l parallel with the linie ol? said body, cutters inounted Within tbe Ways und having' eutting edges adapted to extend hiterally out itroin the Ways, spliced apart rider surfaces on the eon'lfrontingi` serine-en of the cutter-S und bod)v extending;` [.nirnllel with said Ways, ineens Yl'or normally ringing` the cette he over the rider su 'feces to the reaniing position, and llneliing duetr; in the body and eonnnuni nliiig` with the ways in Wliivli the euttern are mounted, thereby to diselnn'g-re flushing i'iuid :it the lower end olf the cutters.

6. In a rotary well nnderreznner, ci body having longitudine-l undercut Ways; extending parallel with the axis or' :said biz-dy, reznning blades slidzible in se'd u'uys and having elongated Substfnitizilly vertical entlingi' edges adzrg'ited to extend laterally outward iiroin Seid waffe in the roaming'y position, spaced apart rider Surfaces between the re; inine blades and body, entendiney parallel with said Ways, Ylor translating the remuer blades to and vlroni the reznning position uplongitudinal motion of the remngaging the )wer end oil eueli rean'iing' blades, :in d nieaneA yieldingly urL f and body, ii heed en the head into upward poi to thereby rane-lele the reauner blades ie warning ponilion,

i'. ik rotary iniderieziiner comprising,y 'fr body limrinii` loiuiitudnnilly undercut cutter- Wef es extending" il n olE seid Ways in l'lie reuniiug position, spared ripa t` rider surluees between the reauninf;` blades :ino molly j, u ullel with Seid mzyf. Ylor JVrunsln e' the ree-lining' blades to and troni the re n' poeition upon relative longitudinal Seid rider Surfaces bueh ol? the outtingij edges ot Suid outliers with the cutting edges only extending frein the Ways., the outline` edges beine; elongated substantially vertically, flushing duels extending' tlnfough the body, spring; ineens nornnilly urging the (utters upwardly' Aorer the rider eurlfaees to the reainlinff position, u springy enclosing` chainber in seid body, und a closure for Said elleniber enclosing` the Chamber ilrou'i eoinl'nuniention with seid llueliirui duets.

Signed zit L si ugi'elee` Californie, 'this th dey of @etobeig 1923.

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